This invention relates to cooking apparatus and, more particularly, to a cooking apparatus with non-fibrous insulation. In one embodiment of the present invention, the non-fibrous insulation enhances heat management in a controlled manner.
Cooking equipment is typically insulated using various types of fibrous insulation, such as fiberglass, cellulose, mineral wool, etc. The purpose of the insulation is to serve as a barrier to prevent heat from escaping the oven cavity and elevating the temperature of the exterior portion of the cooking apparatus creating hazardous operating conditions.
Several materials, such as fiberglass, cellulose, and mineral wool are currently used as insulation in cooking equipment. However, these materials have some disadvantages. Some of these materials cause irritation to human skin. This requires assembly personnel to wear protective clothing when handling such materials.
All of these fibrous insulation materials are hazardous to human health, when consumed. This causes a problem when particles of the insulation break off and contaminate food.
In addition, these materials may create air-borne particles that are hazardous to assembly personnel during handling and installation. This necessitates a need for such personnel to use breathing filters. Thus, the cost of production is increased because special precautions must be used when handling fibrous insulation.
Another disadvantage is that fibrous insulation, as used in cooking equipment, is generally bulky material. This requires the cooking equipment to be unnecessarily large in size to house such unwieldy material. The cost of production of cooking equipment is increased because of the extra material that is needed to build a large enough housing for the fibrous insulation to fit. In addition, cooking equipment with this insulation is more expensive to operate because they take up more space during operation. In locations where space is at a premium, the overhead costs of operating cooking equipment with fibrous insulation will be increased.
Another disadvantage is that fibrous insulation absorbs liquid that may effectively reduce its insulating capability over time. This moisture absorption is also detrimental to the long-term life of the oven and its component parts. Furthermore, fibrous materials are not recyclable. Accordingly, there is a need for an improved insulation for cooking equipment that avoids the aforementioned disadvantages.
Furthermore, cooking equipment are generally known in the art to use natural convection as the sole method of heat removal. Accordingly, a need also exists for an efficient and controlled management of heat removal in cooking equipment.
The present invention provides a cooking apparatus having a heatable component that is at least partially insulated by a heat insulating material. The heat insulating material comprises a plurality of metal sheets spaced apart from each other by a separator. The heat insulating material also includes a heat sink that comprises a plurality of metal sheets that are compressed forming a stack.
The heat insulating material includes a heat radiating surface and a heat reflective surface, which are substantially parallel and face opposite directions. The heat reflective surface faces the heatable component, preferably a convection oven. Heat from the convection oven is reflected back towards the oven thereby reducing unwanted heat loss in the oven compartment. Heat is also conducted across the length and width of this surface, preferably an aluminum sheet. Heat is than radiated from this first metal sheet to a second sheet disposed underneath the first metal sheet. This same process is continued to a next underneath sheet, etc., until a last underneath sheet again functions in the same way. This last underneath sheet has a heat radiating surface that faces an air path in the oven compartment.
Passing an air stream through the cooking apparatus from an inlet to an outlet typically creates the air path. The air stream is directed into two paths. The first path includes the controls compartment and the second path includes the oven compartment. The second air path, in the oven compartment, is passed along peaks and troughs on the heat radiating surface. The peaks and troughs are oriented to aid in the management of the airflow through the oven compartment. In addition, heat is radiated from the heat-radiating surface into the air path. Thus, the cooking apparatus is efficiently cooled by directing airflow through the oven compartment, radiating heat into the air path, and controlling the airflow through the compartment by the peaks and troughs.
Preferably, the insulation is non-fibrous insulation in which the metal sheets are spaced apart by a separator. In one preferred embodiment, the present invention provides a non-fibrous insulation having a separator comprising a plurality of embossments. The embossments extend from the metal sheets and maintain the spaced apart relationship. Thus, insulating layers are formed between each metal sheet.
In a second embodiment, the present invention provides a non-fibrous insulation having a separator comprising a metal foil being formed in a geometric spacing pattern, preferably a hexagon. The separator is disposed between each metal sheet to maintain the spaced apart relationship, thereby forming insulating layers.
Other and further objects, advantages and features of the present invention will be understood by reference to the following specification in conjunction with the annexed drawings, wherein like parts have been given like numbers.